Influence of environmental factors on seed germination and seedling emergence of rye (Secale cereale L.) as a volunteer plant in wheat fields

Laboratory and greenhouse experiments were conducted to determine the
effects of drought and salinity stress, temperature, pH and soil depth on rye
germination and emergence in Gorgan University of Agricultural Science and
Natural Resources. Optimum temperature for germination between 25 to 34.51
 
oC
and base and ceiling temperatures were estimated as 3.3 and 40
 
oC, respectively.
This volunteer plant withstanded against salinity stress in respect to germination.
salinity stress up to 257 mM had no effect on rye seed germination, but
germination decreased as salt concentration increased. The drought and salinity
levels were enough for 50% inhibition of maximum germination were as -17.9 bar
and 456 mM, respectively. The optimum pH for germination of ray seeds was
between 4 to 6. Germination at pH 4 to 6 was over 60%, and declined at alkaline
pH levels (pH 7-9). Maximum emergence occurred when the seeds were planted at
2 cm depth. Seedling emergence was higher (70%) for seeds placed at a soil depth
of 2 cm than for those placed on the soil surface (63%). Germination decreased
with increasing depth and no seed emerged from a depth of 8 cm. considering that
rye seeds can germinate under a wide range of environmental conditions, it is not
surprising that it has became a serious invasive weed in wheat fields.